The present invention relates to goggles, more particularly relates to goggles used for skiing or snowboarding.
Goggles of this type are used under very cold weather. Especially when a skier wearing goggles stops sliding, the inner surfaces of goggle lenses are clouded up due to the skier""s body temperature, sweating or the like and an accident is likely to occur because of poor visibility.
To prevent such cloud up of goggle lenses, the following measures (a) and (b) have been conventionally taken:
(a) Method of applying chemical anti-fog treatment to the inner surfaces of goggle lenses
This method provides a certain anti-fog effect when the temperature of the surface of the lens is down to about 0xc2x0 C. or higher. However, in an environment where the temperature of the surface is below 0xc2x0 C., the temperature of the inner surface side of lens plate also lowers below 0xc2x0 C. and water drops produced on the inner surface of lens plate are frozen, and as a result, the treated lens cannot provide a sufficient anti-fog effect.
(b) Method of producing a goggle lens/lenses with two inner and outer lens plates to provide a heat-insulating layer between the inner and outer lens plates
In this method, the heat insulating layer prevents the inner surface of the goggle lens from promptly becoming clouded up even when the temperature of the surface of the goggle lens is below 0xc2x0 C. Therefore this method can provide an anti-fog effect even in an environment where the temperature of the surface of the outer lens plate is below 0xc2x0 C. However, today""s skiing or the like requires a very large quantity of motion, which intensely increase a skier""s body temperature and enhance a skier""s sweating. As a result, a farther higher anti-fog effect is required.
It is, therefore, an object of the present invention to provide goggles which prevent water drops on inner surface of goggle lens from easily becoming frozen and provides a very high anti-fog effect even if the temperature of the surface of goggle lens is below 0xc2x0 C.
Goggles according to the present invention include three lens plates, i.e. inner, intermediate and outer lens plates and inner spaces between the inner and intermediate lens plates and the intermediate and outer lens plates are used as heat insulating layers.
Also, the goggles of the present invention may have a through hole in the intermediate lens plate and a vent hole in the inner and/or outer lens plates. Alternatively, without providing the through hole, vent holes may be formed respectively on the inner and outer lens plates and closed by a moisture blocking means which prevents moisture from passing and allows air to pass. The through hole and the vent hole are preferably provided at positions where the field of vision is not disturbed.
The distance between the adjacent lens plates of the goggles of the present invention may be 1.6 to 2.4 mm, and more preferably 2 mm.
The goggles of the present invention may include spacing frames between the inner and intermediate lens plates and between the intermediate and outer lens plates. And the contacting surfaces between the inner, intermediate and outer lens plates and the spacing frames may be bonded together.